The necessity and use for more efficient construction materials and tools has become evident in view of the greatly increasing costs involved in the construction industry. To this end, a variety of labor saving devices have been developed both from the standpoint of simplifying particular job functions, as well as designing tools to accommodate a given function in a shorter period of time.
It has also become evident in the home construction industry that a wider use is being made of not only mobile homes, but also modular homes. In this connection, it has become desirable to find various efficient means for securing the modular elements or units to a pre-formed foundation or slab, or alternatively, to find more efficient footing systems for mobile homes. It is well known that various tie down systems have been developed with a view toward applying cables for securing mobile homes to the underlying support ground. Such systems, however, have little if any practical use in the field of modular homes. In view of the increasing construction costs, it has now become quite common to employ the modular theory to home construction. Unfortunately, in many such cases, a full foundation is not employed, but rather, only footing systems are employed when assembling modular home units. This, in turn, has required that more efficient footing systems and devices be developed in order to permit ease of construction and assembly of such modular units in position at the home site.
One of the most common footing systems presently employed is to position a plurality of concrete footings spaced peripherally about the area to be covered by the modular units, each of the concrete footings provided with bolts, hooks, or other fastening means cemented directly into the post when pouring the concrete footing in the first instance. The most common concrete post forms and footings which are presently employed are generally poured through a cylindrical tube which is merely inserted in a hole once it is dug and through which concrete is then poured. It will be appreciated that by the use of such systems, the concrete may be poured to any desired level within the cylindrical tube, allowed to dry, and the balance of the tube above the level of the concrete may then be severed such that the entire concrete post with the tube encircled thereabout is left in position and the open area around the post and form is then backfilled with earth. It will further be appreciated that when such systems are employed, the entire post footing is of a unitary dimension and diameter throughout. It is apparent, however, that it would be far preferable to permit the installation of a post footing wherein the lower end of the post footing has a greater cross sectional diameter then the upper portion of the post footing thereby to yield greater stability regardless of the angle of pressure against the post which is held in position. However, in order to provide a post footing wherein the lower portion is of a greater cross sectional diameter than the upper portion, fairly elaborate concrete forms have been utilized. Furthermore, when pouring concrete through the typical cylindrical tube, it is difficult to maintain the tube in a vertically positioned location within the hole since concrete is often poured via the chutes on the concrete truck and any significant amount of contact between the cylindrical tube and the chute has the tendency to cock the form making it difficult to subsequently position the form in a proper vertical position.
In order to attempt to correct the last mentioned problem, stabilizing systems have been used which consist of stabilizer rods nailed or taped to the upper portion of the cylindrical concrete post form and having the opposed ends staked into the ground. It will be appreciated, however, that the function of nailing, taping, or otherwise affixing the stabilizer rod to the post form directly, is a labor consuming job, and in many instances, the point of attachment of the stabilizer rod to the post form is something less than completely secure.
Other difficulties have similarly been experienced with the post footing systems presently in use. For example, the positioning of the post form at the bottom of a post hole, can in many instances cause the resulting post footing to be cocked away from a perfectly 90.degree. vertical angle. This, obviously, is dependent upon the configuration of the bottom of the hole, and in view of the fact that the post form tends to be a cylindrical tube, should the bottom of the hole have ridges or rises in it, it is difficult, if not impossible, to position the post form in a perfectly vertical position. In addition, as was indicated above, where the post form is inserted into the complete depth of the post hole, it is not possible to obtain a post footing wherein the bottom portion of the fitting has a cross sectional diameter greater than the diameter of the post form at a higher level.
The patented art has attempted to provide solutions to these problems in various forms. For example, U.S. Pat. No. 3,024,512 shows a disposable concrete form for posts and columns wherein there is provided a sleeve which may be of any desired parametrical configuration, the sleeve accommodating the positioning of reinforcing rods inserted therethrough. It will be noted that the concrete form and system as shown in U.S. Pat. No. 3,024,512 attempted to overcome various of the problems noted, such as, for example, the stability of the lower portion of the form at the upper end of the hole. It will be noted that the form is provided with flaps which are designed to rest against the upper surface of the hole while the reinforcing rods are inserted through the sleeve and into the hole. Some degree of vertical stability is achieved by driving one of the reinforcement rods into the ground at the bottom of the post hole. Presumably, the concrete or other post footing material is poured through the sleeve and exits at the bottom of the hole thereby to form the post footing. However, it will be noted that the system does not provide for stabilizer rod tie means, and even more importantly, it will be noted that the entire footing below ground level is completely unidimensional and does not include a portion at the lower end thereof which is of a greater cross sectional diameter than the upper portion of the footing. Other problems are similarly evident from a view of the device shown in U.S. Pat. No. 3,024,512 which bear upon the vertical stability thereof when positioned within the hole, as well as a host of other problems.
As was indicated previously, the art has attempted to solve the problem of having a greater cross sectional diameter of the footing at the lower end of the form, however, such attempts have usually entailed the provision of complicated molds or forms. For example, Patent 1,627,754 shows a mold for footings wherein the mold is constructed to provide an enlarged conical lower section such that the entire post and footing therefor is in a greater degree of vertical and horizontal stability once the footing concrete has dried. It will be observed, however, that the mold is a complicated device and certainly does not lend itself to ease of use in the field.
It will further be appreciated that once the footing has been poured and dried, it is necessary to remove the molds since obviously, it is an expensive item and cannot simply be left in the ground. Hence, this particular solution to the problem has not been adequate nor has the same been employed as a practical matter.
Another attempt at solving the same problem is shown in the art in U.S. Pat. No. 2,448,883 wherein a concrete post form having a conically enlarged lower section is disclosed. However, once again, the subject patent teaches the use of a complete mold, including the lower conical section, in order to achieve the desired end. As indicated previously, it is believed that this is an inefficient system for resolving this problem given the expense of a mold, as well as the expense of labor associated with erecting the mold and disassembling the mold after useage.
Still other solutions are shown in a variety of other prior art patents. For example, Patent 1,119,711 shows another form of a standing concrete post form which includes reinforcing rods inserted through the center portion of the form and which further include a plurality of radially extending plates adjacent the portion of the form which is at ground level for stabilizing purposes. It will be noted, however, that the variety of problems noted hereinabove certainly are not resolved by the subject patent. In point of fact, molds of this type would certainly not be used in a labor market wherein there is labor associated with both erecting and disassembling the mold or form.